1. Field of the Invention
The present invention relates to a portable radio device, such as a cell phone set, a data communication terminal device, etc. provided with an antenna for GPS (Global Positioning System) which can receive location data by the GPS.
2. Description of the Related Art
Because a portable radio device such as a cell phone set, a handy type cell phone set, a mobile data communication terminal device has become popular, and is people carrying the portable radio devices have increased, there are more and more cases in which reports of accidents or crimes are issued from the portable radio devices. However, in contrast with a fixed telephone set which is installed at home, a place where the report has been issued, in short, a place where the accident has happened cannot be known from the portable radio device, although only the telephone number can be detected. Therefore, it is necessary to confirm about the place with a reporter of the accident. In this case, it happens many times that the reporter of the accident is unable to tell the place of occurrence of the accident, when the reporter is not a resident of the place, but he is a simple passenger.
Under the circumstances, in recent years, there has been proposed a system in which function of obtaining location data of individuals with high accuracy is installed in the portable radio device, and the location data of the individuals are urgently communicated to a police or a fire department by way of a base station of a cellular phone or the like. In this case, it is advantageous that function of receiving GPS radio wave making use of a GPS satellite which has been used for car navigation is installed in the portable radio device, thereby to obtain location data of individuals with an accuracy of about 125 m in radius.
FIG. 10 is an outside view of a portable radio device in which the function of receiving the GPS radio waves is installed. In this portable radio device 1, an antenna 2 capable of extending and contracting for cell phone which is used on occasion of telephone conversation is provided exclusively at one side of the portable radio device 1 in a lateral direction, and a chip antenna 4 for receiving the GPS radio waves which is mounted on an incorporated base board 3 is provided at the other side of the cell phone set 1 in a lateral direction, so that a distance X between the two antennas 2 and 4 may be as large as possible.
In case where the function of receiving GPS radio waves is installed in the portable radio device, since a frequency zone of the radio waves used for telephone conversation on the portable radio device is different from a frequency zone of the GPS radio waves, the individual antennas must be separately installed in the small portable radio device. However, in case where the two antennas are arranged close to each other, the radio performance of the respective antennas may be deteriorated, and therefore, it is necessary to arrange the two antennas as remote as possible from each other. Nevertheless, in the example as shown in FIG. 10, a distance between the two antennas 2 and 4 is limited to a lateral width of the portable radio device at most, and deterioration of the radio performance will not be avoided.
Moreover, there are some portable radio devices having function as a transceiver in addition to the function as telephone, and it is necessary to install, in the same small housing, an antenna for short-range wireless communication for the case where the portable radio device is used as the transceiver, separately from the above described two antennas 2, 4. Therefore, there is a problem that the three antennas in total must be arranged in a such a manner that the radio performance may not be deteriorated.
The portable radio device in recent years has become smaller and smaller, into such a size as can be housed in a man's palm. For this reason, almost all parts of the portable radio device are enclosed with a hand while the portable radio device is used, and so, there is a problem that when an antenna part is enclosed with the hand, transmitting and receiving performances of the antenna may be deteriorated.
The present invention has been made in view of the above described circumstances, and an object of the invention is to provide a portable radio device in which when both an antenna for cell phone and an antenna for GPS are installed, or an antenna for short-range wireless communication is installed in addition, bad effects on radio performance by the respective antennas will be decreased, and deterioration of the radio performance when the antennas are enclosed with hands can be avoided.